The invention relates to a belt buckle for a seat belt.
Especially in the case of belt buckles coupled to a belt tensioner, there is the risk of the belt buckle opening automatically due to the high acceleration at the beginning or at the end of belt tensioning, if great inertia forces act on the components of the belt buckle. Release locks that are intended to prevent the belt buckle from opening inadvertently are known in different designs.
EP 0 557 983 A1 illustrates a seat belt buckle comprising a latch lock in which in the case of great mass forces a latch pin serving as locking element is safely retained in a locking position in that its trajectory is blocked in a gate by a latch element. The latch element is a swivel body rotatably supported on the housing of the belt buckle which is movable with a free first arm into a locking position in which it secures the latch pin against movement out of the locking position. The swivel body includes a bent second arm for actuating and pivoting the swivel body by the release button of the belt buckle into a position releasing the latch pin. The second arm is connected to the release button at its free end via a crank mechanism.
From EP 0 823 223 A2 a belt buckle comprising the features of the preamble of claim 1 is known. In said belt buckle a multi-arm latch lever pivoted about a rotational axis on the housing of the belt buckle for preventing automatic displacement of the release button is provided. A first arm of the latch lever is articulated to the release button, while a swivel body is movably supported on a second arm so that upon abrupt change of speed in one direction of movement it transmits an inertia force to the second arm, wherein in the opposite direction the force transmission from the swivel body to the latch lever is interrupted by a movement relative to the second arm.